Streaming media is commonly used to deliver television programs, movies and other digital media content over the Internet and other networks. At present, a variety of streaming audio, video and/or other media content is available to consumers from any number of diverse sources. A large amount of video-on-demand (VOD) content, for example, is now available for network streaming from many different sources. Media streams are also used to deliver other types of media content including live and pre-recorded broadcast television, so-called “Internet (or IP) television”, stored media content (e.g., content stored in a remotely-located digital video recorder (DVR)), placeshifted media content and many others.
More recently, adaptive techniques have been developed to improve the performance of many media streaming applications. Typically, an adaptive media stream is encoded at different bit rates into multiple sets of “streamlets” or other smaller segment files that can be individually requested and adaptively delivered to a particular client device. As changes in processing resources, network bandwidth and/or other factors occur, the client device is able to adapt to the changes by requesting future segments that are encoded with different quality parameters (e.g., a higher or lower bit rate). Adaptive streaming is therefore relatively flexible in responding to different network conditions. A common disadvantage of adaptive streaming, however, is that content needs to be encoded multiple ways at different bit rates which typically need to be made available so that the client can mix and match segments between copies as needed. Several examples of adaptive streaming systems and techniques are described in US Patent Publication No. 2008/0195743, which is incorporated herein by reference, although other techniques could be equivalently used.
Consumers have also expressed significant interest in placeshifting of media programming from one viewing location to another. In a typical placeshifting application, a program that would ordinarily be shown on the viewer's home television is instead transported to a phone, tablet, portable computer or other device at a different location. Placeshifting can be used to provide remote access to programming stored on a viewer's personal video recorder (PVR), for example, or to shift viewing of live programs from one television set to another, or for any number of other useful purposes. Traditionally, placeshifted media streams are encoded in real time as they are transmitted to the remote device.
Substantial difficulties can arise, however, in placeshifting an adaptive media stream. Adaptive streams typically rely upon the simultaneous availability of multiple pre-encoded copies of the media program; these multiple copies can be difficult to produce in real time to support conventional placeshifting applications.
It is therefore desirable to create systems, device and methods to reliably, effectively and securely placeshift adaptive media streams between media devices. These and other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background section.